Add Command to "Set Title" for Window

[osterman]

Is your feature request related to a problem? Please describe.
Add an optional "Title" for the output video.

Describe the solution you'd like
I came across this VHS-style demo gif. It's almost identical to what VHS generates, but has once nice addition: a title ("Bit").

From: https://github.com/chriswalz/bit/tree/master

Ideally, we would be able to set something like this...

Set Title "Demo of Tool"

So, for example to reproduce the above output, we would configure:

Set WindowBar Colorful
Set Title Bit

Describe alternatives you've considered

• N/A

Additional context

• N/A

[nixpig]

Also needed this and currently working on implementing.

I'm happy to submit a PR when it's ready, if contributions are welcome?